Many types of manufactured parts, such as parts used in the manufacture of aircrafts, automobiles and machinery, may be coated with various materials and substances (e.g., paint) to adapt the part for its intended purpose. In many of these coating operations, the surface of the part may be completely exposed to the coating substance. Many types of parts may include features that must not be coated. The part may include inner surfaces through which coating substances could enter the part and undesirably come into contact with the internal surfaces of the part. For example, the part may include fastening openings (e.g., countersunk holes) that must remain free from the coating substance and other debris.
It may be undesirable to apply a coating substance to the internal surfaces of these types of parts for many reasons. For example, it may be undesirable to apply paint to the internal surfaces of a fastening opening because the paint may interfere with an installed fastener. It may also be undesirable for the coating substance to come into contact with the internal surfaces of the opening because the coating substance may damage the internal surface of the part.
Various approaches have been used to mask, or temporarily close, the openings in the parts, thereby preventing the coating substance from coming into contact with the internal surfaces of the opening, including masking tape dots or flexible plugs. These approaches may be less than adequate in completely sealing off a coating from the interior of a part. There may also be issues with the introduction of foreign object debris or with material compatibility.
Accordingly, those skilled in the art continue with research and development efforts in the field of masking openings in parts during a coating operation.